namespace HSchool.Simulation.Tests;

public class ClockTempoTests
{
    private static readonly DateTime Start = new(2012, 4, 3, 6, 0, 0, DateTimeKind.Utc);

    private const double OneTwentiethOfASecond = 1d / 20d;
    private const double GameMinutesPerRealSecond = 1d;

    [Fact]
    public void AtX10_TwentyImpulses_RunHeavyTenTimesAndAdvanceTenGameMinutes()
    {
        using var school = School.Create(1, "Страйд", Start);
        school.Clock.SpeedIndex = 4;

        for (var i = 0; i < 20; i++)
        {
            school.Tick(OneTwentiethOfASecond, GameMinutesPerRealSecond);
        }

        Assert.Equal(Start.AddMinutes(10), school.Clock.Time);
        Assert.Equal(10, school.HeavySystemsInvocations);
        Assert.Equal(1d, school.LastHeavyGameMinutes);
    }

    [Theory]
    [InlineData(0, 0.5)]
    [InlineData(1, 1d)]
    [InlineData(2, 2d)]
    public void LowSpeed_EveryImpulseRunsHeavySystems(int speedIndex, double expectedMinutes)
    {
        using var school = School.Create(1, "Каждый импульс", Start);
        school.Clock.SpeedIndex = speedIndex;

        for (var i = 0; i < 20; i++)
        {
            school.Tick(OneTwentiethOfASecond, GameMinutesPerRealSecond);
        }

        Assert.Equal(Start.AddMinutes(expectedMinutes), school.Clock.Time);
        Assert.Equal(20, school.HeavySystemsInvocations);
    }

    [Fact]
    public void AtX5_TwentyImpulses_RunHeavyFiveTimesAndAdvanceFiveGameMinutes()
    {
        using var school = School.Create(1, "Страйд ×5", Start);
        school.Clock.SpeedIndex = 3;

        for (var i = 0; i < 20; i++)
        {
            school.Tick(OneTwentiethOfASecond, GameMinutesPerRealSecond);
        }

        Assert.Equal(Start.AddMinutes(5), school.Clock.Time);
        Assert.Equal(5, school.HeavySystemsInvocations);
        Assert.Equal(1d, school.LastHeavyGameMinutes);
    }

    [Theory]
    [InlineData(3, 5d)]
    [InlineData(4, 10d)]
    public void HighSpeedIndex_OneRealSecond_AdvancesExpectedGameMinutes(int speedIndex, double expectedMinutes)
    {
        using var school = School.Create(1, "Быстро", Start);
        school.Clock.SpeedIndex = speedIndex;

        for (var i = 0; i < 20; i++)
        {
            school.Tick(OneTwentiethOfASecond, GameMinutesPerRealSecond);
        }

        Assert.Equal(Start.AddMinutes(expectedMinutes), school.Clock.Time);
    }
}